This invention relates to a high pressure fuel feeding system for a fuel injected engine and more particularly to an improved fuel feed system and fuel injection system for an internal combustion engine and particularly that of an outboard motor.
The advantages of fuel injection in maintaining good fuel economy and low exhaust emissions are well acknowledged. For this reason, fuel injection systems are being considered for a wide variety of engine applications. One application where fuel injection has considerable advantages is in the power head of an outboard motor.
One problem particularly acute in conjunction with outboard motors is that the entire engine and most of its supporting systems must be provided in a relatively compact and confined area within the power head of the outboard motor. This can give rise to certain problems, particularly when fuel injection systems are employed. For example, it is the practice to employ a high pressure pump that delivers fuel under pressure to the fuel injectors of the engine. In order to assure good injection control, however, it is also necessary to provide some form of pressure regulation in the high pressure system supplying the fuel injectors. The pressure is normally regulated by returning excess fuel back to the inlet side of the high pressure pump or to a storage tank contained within the power head. However, this adds significantly to the number of conduits and connections in the injection system and particularly the fuel supply side.
Of course, fuel leakage is always a problem with any type of system. However, the leakage can be a particularly acute problem in conjunction with outboard motors wherein the components are all located close to each other and within a confining protective cowling.
It is, therefore, a principal object of this invention to provide an improved arrangement for insuring against external fuel leakage in the fuel injection system for an engine.
It is a further object of this invention to provide an improved high pressure fuel injection system for an outboard motor and the engine associated therewith.
In addition to the actual conduits that convey the fuel from the pressure pump to the fuel injectors and pressure regulator, there is also a problem of potential leakage in the individual components of the system. In addition to a high pressure pump, a fuel injector and a pressure regulator, it is also the practice frequently to employ additional components in the fuel injection system. For example, a vapor separator is frequently employed in such engines to insure that only liquid fuel is pumped and supplied to the fuel injectors.
It is, therefore, a still further object of this invention to provide an improved arrangement for insuring against external leakage of the various components of the fuel injection system.
It is a further object of this invention to provide an improved arrangement for encapsulating components of the fuel injection system within a container so that any fuel that may leak can be accumulated in this container and cannot come into contact with the engine itself.
Another problem particularly acute with outboard motors is the actual placement of the various components of the fuel injection system relative to the engine. For example, fuel injection systems may be employed in conjunction with V-type engines having angularly disposed cylinder banks. If all of the components are located at one side or the other of the engine, then conduitry must extend back and forth between the cylinder banks and the difference in length of the conduits must be taken into effect in designing the pressure regulation and capacity of the various components.
It is, therefore, a still further object of this invention to provide an improved layout for the fuel injection system components of a V-type engine.
It is a yet further object of this invention to provide an improved fuel injected V-type engine for an outboard motor.
One type of fuel injection system employs injectors which inject not only fuel under pressure but also air under pressure to the engine. With this type of system, the components can become more complicated in that in addition to the fuel pump and pressure regulation for the fuel side of the system, there must also be provided an air compressor and a pressure regulator for the air compressor. In addition, since air and fuel are both supplied to the fuel injectors, there is a possibility that fuel may enter into the air system.
For example, if there is provided an air pressure regulator in the conduit that supplies the fuel/air injectors, the regulation of air pressure by returning some of the air back to the air compressor, can cause fuel to be returned along with air to the air compressor. If fuel vapors are present in the air pumped by the air compressor, then a number of difficulties can arise, for example high power requirements for driving the air compressor.
It is, therefore, a still further object of this invention to provide an improved air supply system for a fuel/air injector arrangement for an internal combustion engine.
It is a further object of this invention to provide an improved vapor separator for the air pressure system of a fuel/air injection system.